triplex pump design.pdf

Upload: protozua-academe

Post on 29-Oct-2015

235 views

Category:

Documents


47 download

DESCRIPTION

Triplex Pump Design.pdf

TRANSCRIPT

  • Design of Triplex Plunger Pump

    Abdullah Al-JubranAli Al-Qahtani

    Haitam Al-Mubarak

    Project Advisor: Dr. Emad TanbourA Design Project Submitted in Partial Fulfillment

    of the Requirements for the Course

    Assessment III: Graduation Project

    College of EngineeringDepartment of Mechanical Engineering

  • Statement of Purpose

    To design a triplex plunger pump that can bemanufactured using locally available resources and manufacturing techniques

    To practice the application of computer-aided design program in the design of machines

    College of EngineeringDepartment of Mechanical Engineering

  • Table of Contents

    Introduction Scope of Project Pumps Classification Triplex Pump Basics/Concept Calculations Crankshaft Diameter Bearings Triplex Pump Prototype

    College of EngineeringDepartment of Mechanical Engineering

  • Introduction

    Triplex Plunger Pump Positive Displacement Pump Three Plungers in parallel High-Pressure Low-Capacity Application

    hydrostatic testing water blasting surface preparation car washing pipe and tube cleaning oil drilling

    College of EngineeringDepartment of Mechanical Engineering

  • Scope of Project

    Designing of Triplex Plunger PumpDischarge Pressure: 350 bar (5,076 psi)Flow Rate: 24 li/min (6.3 gpm)

    Crankshaft Bearings Material Selection Fasteners

    Making of Digital Prototype

    College of EngineeringDepartment of Mechanical Engineering

  • Design Approach

    Group Brainstorming Gather Literatures from the web Design Conceptualization Identification of Critical Components Sizing and Strength Calculations Prototyping by CAD Solidworks

    College of EngineeringDepartment of Mechanical Engineering

  • Triplex Pump Design GANTT Chart

    College of EngineeringDepartment of Mechanical Engineering

  • Positive Displacement Pump versus Centrifugal Pump

  • Classification Diagram of Displacement Pumps

  • Classification Diagram of Displacement Pumps

  • Reciprocating Positive Displacement Pumps

    1. Piston Pump 2. Plunger Pump 3. Diaphragm Pump Higher Pressure Suitable for Chemicals Good packing life

    Expensive Good for slurries Easier to maintain

  • Ways to Achieve Reciprocating Motion

    1. Crankshaft with crank pin

    2. Crankshaft with eccentric sheave or strap

  • Slider Crank Mechanism

    The offset between the shaft center and eccentric sheave center determines the pump stroke

  • Plunger Pump with Eccentric Sheave

  • Critical Componentsa. Crankshaftb. Eccentric Sheavec. Crankshaft Support Bearingd. Eccentric Sheave Bearinge. Wrist Pinf. Wrist Pin Bearing g. Fluid End Plunger

  • Design CalculationsCriteria: Displacement: 24 li/min

    Discharge Pressure: 350 bar# of Plungers: 3

    Computation to determine required powerkW = Q Ptd / 36 ME

    Where Q = delivered capacity, m3/hPtd = differential pressure (discharge suction), barME = mechanical efficiency, %

    At 24 liters/minute, 350 bar and typical efficiency of 88%,

    (24 liters/min)(60min/hr)(1m3/1000liters)(350bar)(360.88)kW =

    kW = 15.91 kilowatts, or 21.33 Hp

  • Computation to determine Pump Speed and Plunger Speed

    Q = A m n s 6 10-8Sp = s n / 30,000

    From Pump Handbook, 3rd edition, pages 3.4, 3.6

    Where Q = displacement, m3/hSp = plunger speed, m/sA = cross-sectional area of plunger, mm2M = number of plungersn = rpm of pumps = stroke of pump, mm

    Preselected Plunger Bore and Stroke

    Plunger Bore Size : 18, 19, 20, 21 and 22 mm

    Plunger Stroke : 21, 22, and 23 mm

  • Plunger Bore, mm Plunger Stroke, mm

    Pump Speed, rpm Plunger Speed, m/s

    1821 1,497 1.0522 1,429 1.0523 1,367 1.05

    1921 1,344 0.9422 1,283 0.9423 1,227 0.94

    2021 1,213 0.8522 1,158 0.8523 1,107 0.85

    2121 1,100 0.7722 1,050 0.7723 1,004 0.77

    2221 1,002 0.7022 957 0.7023 915 0.70

    Table 1 Pump Speed at Different Plunger Bore and Stroke

  • The obtained plunger speeds above are in accordance with the industry standard

  • Computation to determine Pump Required TorqueFrom Pump Handbook, 3rd edition, page 3.8

    M = p 9.549 / nWhere M = pump torque, Nm

    n = speed, rpmp = power, W

    Plunger Bore, mm Plunger Stroke, mm

    Pump Speed, rpm Torque, Nm

    1821 1,497 10222 1,429 10623 1,367 111

    1921 1,344 11322 1,283 11823 1,227 124

    2021 1,213 12522 1,158 13123 1,107 137

    2121 1,100 13822 1,050 14523 1,004 151

    2221 1,002 15222 957 15923 915 166

  • a. Calculation to Determine Crankshaft Diameter

  • a. Calculation to Determine Crankshaft Diameter

    Where D = shaft diameter, mmKt = shock and endurance factor applied to computed twisting

    moment (Table 14-2 Machine Design Data Book, 2nd ed. page 14.18)

    Mt = twisting moment or torque, Nmyd = design yield stress, Pa

    From Machine Design Data Book, 2nd edition, page 14.3

    16piyd

    Kt MtD = 1000

    For rotating shafts with dynamic load, dynamic effect taken indirectly into consideration

    The diameter of shaft subjected to simple torsion

  • From Machine Design Data Book, 2nd edition, page 14.18

  • Using AISI 1020 steel which has a yield strength of about 206 MPa, and using a design factor of 1.5,

    max = 206 MPa 10^6 Pa/MPa(2 1.5)max = 68,666,666 Pa

    From Shigley's Mechanical Engineering Design, 8th Edition, page 212

    max = Sy / 2n

    Where max = maximum shear stress, PaSy = yield stress, Pan = design factor

    163.1415 68,666,666

    1.5 MtD =

    1000

  • Plunger Bore, mm

    Plunger Stroke, mm

    Pump Speed, rpm

    Pump Torque, Nm

    Computed Shaft

    Diameter, mm

    1821 1,497 102 22.422 1,429 106 22.823 1,367 111 23.1

    1921 1,344 113 23.322 1,283 118 23.623 1,227 124 24.0

    2021 1,213 125 24.122 1,158 131 24.423 1,107 137 24.8

    2121 1,100 138 24.922 1,050 145 25.323 1,004 151 25.6

    2221 1,002 152 25.622 957 159 26.023 915 166 26.4

    Table 1: Computed Shaft Diameter at Different Plunger Bore and Stroke

  • b. Calculation to Determine Eccentric Sheave Diameter

    Sd2 = (s/2) + (D/2) + sw

    Where Sd = eccentric sheave diameter, mms = plunger stroke, mmD = shaft diameter, mmsw = minimum sheave width, mm

    - pre-selected to be 4.7625 mm (3/16 inch) to facilitate easywelding of the eccentric sheave to the shaft

  • Plunger Bore, mm

    Plunger Stroke, mm

    Computed Shaft Diameter, mm

    Ecc. Sheave Diameter, mm

    1821 22.4 53.022 22.8 54.323 23.1 55.7

    1921 23.3 53.822 23.6 55.123 24.0 56.5

    2021 24.1 54.622 24.4 56.023 24.8 57.3

    2121 24.9 55.422 25.3 56.823 25.6 58.2

    2221 25.6 56.222 26.0 57.623 26.4 59.0

    Table 2: Eccentric Sheave Diameter at Different Shaft Size

  • c. Calculation to Determine Strength of Eccentric Sheave Weldment

    Stresses in welded joints in torsion" = Mr / J

    Where = shear or torsional stress, PaM = torsional moment, Nmr = distance from the centroid of the weld group to the point in the weld

    of interest, mJ = second polar moment of area, m4

  • For circular fillet welds

    Ju = 2 pi r3

    The distance from the centroid of the weld group to the point in the weld of interest, r, can be taken as the radius of the shaft.

    The force exerted by the plunger

    Fp = Pressure Plunger Cross-Sectional Area

    Example, 22mm plunger bore

    Fp = (350 bar) (100KPa/bar) (1000Pa/Kpa) (1N/m2/Pa) pi (22mm/1000mm/m)2/4

    Fp = 13,304 N

    Maximum moment = Fp (stroke/2). For 23mm stroke, M = 13,304 N (23mm/1000mm/m) 2M = 153 Nm

    J = 0.707hJu

  • By using the results above, the stress on the 3/16 inch fillet weld can be calculated.

    (153Nm)(27mm/1000mm/m)2(0.707)(3/16in.)(1m/39.37in.)(23.1415)((27mm/1000mm/m)2)3" =

    " = 39,682,448 N/m2 or 39.7 MPa (5.473 ksi)

  • c. Calculation to Determine Crankshaft Bearing

    Bearing Catalog Load Rating

    C10 =1/a

    FDLDnD60LRnR60

    Where C10 = catalog load rating, kNFD = desired radial load, kNLD = desired life, hoursnD = desired speed, rev/minLR = rating life, hoursnR = rating speed, rev/mina = constant; a = 3 for ball bearings, a = 10/3 for roller bearings

    For most bearing manufacturers LRnR60 = 106

    C10 =1/a

    FDLDnD60

    106

  • Forces acting on the crankshaft bearing

    Total maximum force acting on the bearing

    Fb1 = 12 Fp2 +

    34

    Fp1

    Fb1 = 54 Fp

    Where Fp = Pressure Plunger Cross-Sectional Area

    Fp = (350 bar) (100KPa/bar) (1000Pa/Kpa) (1N/m2/Pa) pi (bore in mm/1000mm/m)2/4

    = Fbmax

  • Plunger Bore, mm

    18 19 20 21 22FP, kN 8.91 9.92 11.0 12.12 13.30Fbmax 11.13 12.40 13.74 15.15 16.63

    Table 3: Maximum Bearing Load at Different Plunger Bore Sizes

  • Plunger Bore, mm18 19 20 21 22

    FP, (kN) 8.91 9.92 11.0 12.12 13.30Fbmax, (kN) 11.13 12.40 13.74 15.15 16.63nD, (rpm) 1,497 1,344 1,213 1,100 1,002

    LD, (hours) 5,000 5,000 5,000 5,000 5,000C10, (kN)

    (ball bearing) 85.25 91.64 98.12 104.71 111.40C10, (kN)

    (roller bearing) 69.55 75.03 80.61 86.31 92.11Computed Shaft

    Dia, (mm) 23.1 24.0 24.8 25.6 26.4Std. Shaft Dia., (mm) 25 25 25 30 30AvailableBearing - - - - -

    Table 4: Shaft Bearing Load Rating

  • Plunger Bore, mm18 19 20 21 22

    FP, (kN) 8.91 9.92 11.0 12.12 13.30Fbmax, (kN) 11.13 12.40 13.74 15.15 16.63nD, (rpm) 1,497 1,344 1,213 1,100 1,002

    LD, (hours) 5,000 5,000 5,000 5,000 5,000C10, (kN)

    (ball bearing) 85.25 91.64 98.12 104.71 111.40C10, (kN)

    (roller bearing) 69.55 75.03 80.61 86.31 92.11Computed Shaft

    Dia, (mm) 23.1 24.0 24.8 25.6 26.4Initial Std. Shaft

    Dia., (mm) 25 25 25 30 30Adjusted Std.

    Shaft Dia., (mm) 30 30 30 30 30Available

    Bearing, SKFNU 2306NJ 2306

    NU 2306NJ 2306

    NU 2306NJ 2306 - -

    Table 4: Shaft Bearing Load Rating

  • Available SKF Bearing for the crankshaft

  • Plunger Bore, mm18 19 20

    FP, (kN) 8.91 9.92 11.0nD, (rpm) 1,497 1,344 1,213

    LD, (hours) 5,000 5,000 5,000C10, (kN)

    (ball bearing) 68.20 73.31 78.50C10, (kN)

    (roller bearing) 55.64 60.02 64.49Eccentric Sheave

    Internal Dia., (mm) 30 30 30Eccentric Sheave

    Outside Dia., (mm) 60 60 60

    Available Bearing, SKF

    NKIS 60NA 4912

    NKI 60/35

    NKIS 60NA 4912

    NKI 60/35

    NKIS 60

    Table 5: Eccentric Sheave Bearing Load Rating

  • e. Pump Driver Selection

  • e. Pump Driver Selection

  • e. Pump Driver Selection

    Manufacturer Hp Speed, rpm Efficiency,% Cost, $ Cat. No.

    GE25 1,200 91.7 2,312 S279

    25 1,200 93.0 2,800 M7549

    Baldor 25 1,200 93.0 5,090 ECP4111T

    Siemens 25 1,200 91.7 2,480 1LE29313AC116AA3

    TECO Westinghouse

    25 1,200 91.7 3,438 N0256

    25 1,200 93.0 4,456 EP0256

    25 1,200 93.0 4,635 HH0256

    Table 6: List of Applicable Drive Motors

  • e. Pump Driver Selection

    Manufacturer Hp Speed, rpm Efficiency,% Cost, $ Cat. No.

    GE25 1,200 91.7 2,312 S279

    25 1,200 93.0 2,800 M7549

    Baldor 25 1,200 93.0 5,090 ECP4111T

    Siemens 25 1,200 91.7 2,480 1LE29313AC116AA3

    TECO Westinghouse

    25 1,200 91.7 3,438 N0256

    25 1,200 93.0 4,456 EP0256

    25 1,200 93.0 4,635 HH0256

    Table 6: List of Applicable Drive Motors

  • Plunger Bore,mm

    Plunger Stroke, mm Speed, rpm Remarks

    1821 1,497

    Disregarded. Motor speed is only1,200 rpm.22 1,429

    23 1,367

    1921 1,344

    Disregarded. Motor speed is only1,200 rpm.22 1,283

    23 1,227

    2021 1,213 Disregarded. Motor speed is only 1,200 rpm22 1,158 Selected Plunger Bore & Stroke23 1,107 Disregarded. Not optimal.

    2121

    Disregarded. No crankshaft bearing available.2223

    2221

    Disregarded. No crankshaft bearing available.2223

    Selected Plunger Bore and Stroke

  • Since the standard shaft diameter chosen is 30mm, and the eccentric sheave diameter is 60mm, the minimum sheave thickness, sw, is recalculated.

    Sd2 = (s/2) + (D/2) + sw

    From

    sw =Sd - s - D

    2

    sw =60 - 22 - 30

    2= 4 mm

  • f. Calculation to determine wrist pin sizeAISI 1030 steel is chosen because of higher yield strength than AISI 1020 steel.

    Based on maximum shear stress theory, the maximum allowable shear stress,

    max = Sy / 2n

    Where the yield strength, Sy, for 1030 steel is equal to 260 Mpa. Using a design factor of 1.5,

    max = 260 / (21.5) = 86.7 Mpa

  • f. Calculation to determine wrist pin size (contd)Wrist pin will fail by shearing on sections a and b.

    max = Fp / (Aa + Ab)

    But since the cross-sectional area of the wrist pin is the same, therefore Aa=Ab, then,

    Where A = cross-sectional area of wrist pin.

    max = Fp / 2A = Fp 2(pidw2/4) ; dw = wrist pin diameterBy transposing the equation above

    dw = (4Fp/2pi max)1/2

    411kN1000N/kN23.141586.7Mpa106Pa/Mpadw =

    dw = 0.00899m or 8.99mm

    The next preferred size is chosen which is 10 mm.

  • g. Computation to determine the wrist pin bearing

    The bearing size is selected based on the static load rating, C0, because the wrist pin

    Basic static load rating C0

    a. makes a slow oscillating or alignment movements under loadb. rotates under load at very low speed

    C0 = S0 P0Where C0 = basic static load rating, kN

    P0 = equivalent static bearing load, kNS0 = static safety factor

    Based on SKF guideline, for non-rotating roller bearing with normal operations, S0=1. Since P0=11kN, then

    C0 = 111kNC0 = 11kN

    From SKF catalogue, a drawn cup needle roller bearing with C0=11.4kN is available. The bearing designation is HN1010.

  • h. Bill of Materials

    Item Description Specifications Quantity1 Crankshaft 30 mm O.D., AISI 1020 steel 12 Crankshaft Suppport Bearing SKF NU 2306 or NJ 2306 23 Eccentric Sheave 60 mm I.D., AISI 1030 steel 34 Eccentric Sheave Bearing SKF NKIS 60 35 Wrist Pin 10 mm O.D., AISI 1030 16 Wrist Pin Bearing SKF HN 1010 17 Motor GE M7549 1

  • j. Triplex Pump Solidworks Digital Prototype

  • j. Triplex Pump Solidworks Digital Prototype

  • j. Triplex Pump Solidworks Digital Prototype

  • j. Triplex Pump Solidworks Digital Prototype

  • i. Triplex Pump Solidworks Digital Prototype

  • j. Triplex Pump Solidworks Digital Prototype